1. Field
The described technology generally relates to a secondary battery, and more particularly, to a secondary battery having improved safety.
2. Description of the Related Technology
Batteries widely used as power sources of portable devices may be divided into secondary batteries and primary batteries. Unlike the primary batteries of which charge is impossible, the secondary batteries are rechargeable, and thus, they can be used multiple times. The shapes of the secondary batteries may be easily adapted to those of external electronic devices that employ the secondary batteries. As described above, since the secondary batteries can effectively accumulate energy for relatively smaller volumes and masses, they are frequently used as power sources of portable electronic devices.
In particular, with the development of portable communication devices, demands on secondary batteries used for the portable communication devices are increased. Since a problem of safety may occur due to characteristics of the secondary batteries, studies have been conducted in many fields so as to prevent the problem of safety.